From 925ca36913fc7dfee9d0bb7f36d81dd108a7b80f Mon Sep 17 00:00:00 2001 From: Kent Gibson Date: Tue, 16 Jun 2020 17:36:15 +0800 Subject: [PATCH] gpiolib: split character device into gpiolib-cdev Split the cdev specific functionality out of gpiolib.c and into gpiolib-cdev.c. This improves the readability and maintainability of both the cdev and core gpiolib code. Suggested-by: Bartosz Golaszewski Signed-off-by: Kent Gibson Link: https://lore.kernel.org/r/20200616093615.5167-1-warthog618@gmail.com Signed-off-by: Linus Walleij --- drivers/gpio/Makefile | 1 + drivers/gpio/gpiolib-cdev.c | 1154 +++++++++++++++++++++++++++++++++++++++++++ drivers/gpio/gpiolib-cdev.h | 11 + drivers/gpio/gpiolib.c | 1119 +---------------------------------------- 4 files changed, 1170 insertions(+), 1115 deletions(-) create mode 100644 drivers/gpio/gpiolib-cdev.c create mode 100644 drivers/gpio/gpiolib-cdev.h diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index 1e4894e..ef666cf 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -7,6 +7,7 @@ obj-$(CONFIG_GPIOLIB) += gpiolib.o obj-$(CONFIG_GPIOLIB) += gpiolib-devres.o obj-$(CONFIG_GPIOLIB) += gpiolib-legacy.o obj-$(CONFIG_GPIOLIB) += gpiolib-devprop.o +obj-$(CONFIG_GPIOLIB) += gpiolib-cdev.o obj-$(CONFIG_OF_GPIO) += gpiolib-of.o obj-$(CONFIG_GPIO_SYSFS) += gpiolib-sysfs.o obj-$(CONFIG_GPIO_ACPI) += gpiolib-acpi.o diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c new file mode 100644 index 0000000..b8b8727 --- /dev/null +++ b/drivers/gpio/gpiolib-cdev.c @@ -0,0 +1,1154 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "gpiolib.h" +#include "gpiolib-cdev.h" + +/* Character device interface to GPIO. + * + * The GPIO character device, /dev/gpiochipN, provides userspace an + * interface to gpiolib GPIOs via ioctl()s. + */ + +/* + * GPIO line handle management + */ + +/** + * struct linehandle_state - contains the state of a userspace handle + * @gdev: the GPIO device the handle pertains to + * @label: consumer label used to tag descriptors + * @descs: the GPIO descriptors held by this handle + * @numdescs: the number of descriptors held in the descs array + */ +struct linehandle_state { + struct gpio_device *gdev; + const char *label; + struct gpio_desc *descs[GPIOHANDLES_MAX]; + u32 numdescs; +}; + +#define GPIOHANDLE_REQUEST_VALID_FLAGS \ + (GPIOHANDLE_REQUEST_INPUT | \ + GPIOHANDLE_REQUEST_OUTPUT | \ + GPIOHANDLE_REQUEST_ACTIVE_LOW | \ + GPIOHANDLE_REQUEST_BIAS_PULL_UP | \ + GPIOHANDLE_REQUEST_BIAS_PULL_DOWN | \ + GPIOHANDLE_REQUEST_BIAS_DISABLE | \ + GPIOHANDLE_REQUEST_OPEN_DRAIN | \ + GPIOHANDLE_REQUEST_OPEN_SOURCE) + +static int linehandle_validate_flags(u32 flags) +{ + /* Return an error if an unknown flag is set */ + if (flags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) + return -EINVAL; + + /* + * Do not allow both INPUT & OUTPUT flags to be set as they are + * contradictory. + */ + if ((flags & GPIOHANDLE_REQUEST_INPUT) && + (flags & GPIOHANDLE_REQUEST_OUTPUT)) + return -EINVAL; + + /* + * Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If + * the hardware actually supports enabling both at the same time the + * electrical result would be disastrous. + */ + if ((flags & GPIOHANDLE_REQUEST_OPEN_DRAIN) && + (flags & GPIOHANDLE_REQUEST_OPEN_SOURCE)) + return -EINVAL; + + /* OPEN_DRAIN and OPEN_SOURCE flags only make sense for output mode. */ + if (!(flags & GPIOHANDLE_REQUEST_OUTPUT) && + ((flags & GPIOHANDLE_REQUEST_OPEN_DRAIN) || + (flags & GPIOHANDLE_REQUEST_OPEN_SOURCE))) + return -EINVAL; + + /* Bias flags only allowed for input or output mode. */ + if (!((flags & GPIOHANDLE_REQUEST_INPUT) || + (flags & GPIOHANDLE_REQUEST_OUTPUT)) && + ((flags & GPIOHANDLE_REQUEST_BIAS_DISABLE) || + (flags & GPIOHANDLE_REQUEST_BIAS_PULL_UP) || + (flags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN))) + return -EINVAL; + + /* Only one bias flag can be set. */ + if (((flags & GPIOHANDLE_REQUEST_BIAS_DISABLE) && + (flags & (GPIOHANDLE_REQUEST_BIAS_PULL_DOWN | + GPIOHANDLE_REQUEST_BIAS_PULL_UP))) || + ((flags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN) && + (flags & GPIOHANDLE_REQUEST_BIAS_PULL_UP))) + return -EINVAL; + + return 0; +} + +static long linehandle_set_config(struct linehandle_state *lh, + void __user *ip) +{ + struct gpiohandle_config gcnf; + struct gpio_desc *desc; + int i, ret; + u32 lflags; + unsigned long *flagsp; + + if (copy_from_user(&gcnf, ip, sizeof(gcnf))) + return -EFAULT; + + lflags = gcnf.flags; + ret = linehandle_validate_flags(lflags); + if (ret) + return ret; + + for (i = 0; i < lh->numdescs; i++) { + desc = lh->descs[i]; + flagsp = &desc->flags; + + assign_bit(FLAG_ACTIVE_LOW, flagsp, + lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW); + + assign_bit(FLAG_OPEN_DRAIN, flagsp, + lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN); + + assign_bit(FLAG_OPEN_SOURCE, flagsp, + lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE); + + assign_bit(FLAG_PULL_UP, flagsp, + lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP); + + assign_bit(FLAG_PULL_DOWN, flagsp, + lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN); + + assign_bit(FLAG_BIAS_DISABLE, flagsp, + lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE); + + /* + * Lines have to be requested explicitly for input + * or output, else the line will be treated "as is". + */ + if (lflags & GPIOHANDLE_REQUEST_OUTPUT) { + int val = !!gcnf.default_values[i]; + + ret = gpiod_direction_output(desc, val); + if (ret) + return ret; + } else if (lflags & GPIOHANDLE_REQUEST_INPUT) { + ret = gpiod_direction_input(desc); + if (ret) + return ret; + } + + atomic_notifier_call_chain(&desc->gdev->notifier, + GPIOLINE_CHANGED_CONFIG, desc); + } + return 0; +} + +static long linehandle_ioctl(struct file *filep, unsigned int cmd, + unsigned long arg) +{ + struct linehandle_state *lh = filep->private_data; + void __user *ip = (void __user *)arg; + struct gpiohandle_data ghd; + DECLARE_BITMAP(vals, GPIOHANDLES_MAX); + int i; + + if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) { + /* NOTE: It's ok to read values of output lines. */ + int ret = gpiod_get_array_value_complex(false, + true, + lh->numdescs, + lh->descs, + NULL, + vals); + if (ret) + return ret; + + memset(&ghd, 0, sizeof(ghd)); + for (i = 0; i < lh->numdescs; i++) + ghd.values[i] = test_bit(i, vals); + + if (copy_to_user(ip, &ghd, sizeof(ghd))) + return -EFAULT; + + return 0; + } else if (cmd == GPIOHANDLE_SET_LINE_VALUES_IOCTL) { + /* + * All line descriptors were created at once with the same + * flags so just check if the first one is really output. + */ + if (!test_bit(FLAG_IS_OUT, &lh->descs[0]->flags)) + return -EPERM; + + if (copy_from_user(&ghd, ip, sizeof(ghd))) + return -EFAULT; + + /* Clamp all values to [0,1] */ + for (i = 0; i < lh->numdescs; i++) + __assign_bit(i, vals, ghd.values[i]); + + /* Reuse the array setting function */ + return gpiod_set_array_value_complex(false, + true, + lh->numdescs, + lh->descs, + NULL, + vals); + } else if (cmd == GPIOHANDLE_SET_CONFIG_IOCTL) { + return linehandle_set_config(lh, ip); + } + return -EINVAL; +} + +#ifdef CONFIG_COMPAT +static long linehandle_ioctl_compat(struct file *filep, unsigned int cmd, + unsigned long arg) +{ + return linehandle_ioctl(filep, cmd, (unsigned long)compat_ptr(arg)); +} +#endif + +static int linehandle_release(struct inode *inode, struct file *filep) +{ + struct linehandle_state *lh = filep->private_data; + struct gpio_device *gdev = lh->gdev; + int i; + + for (i = 0; i < lh->numdescs; i++) + gpiod_free(lh->descs[i]); + kfree(lh->label); + kfree(lh); + put_device(&gdev->dev); + return 0; +} + +static const struct file_operations linehandle_fileops = { + .release = linehandle_release, + .owner = THIS_MODULE, + .llseek = noop_llseek, + .unlocked_ioctl = linehandle_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = linehandle_ioctl_compat, +#endif +}; + +static int linehandle_create(struct gpio_device *gdev, void __user *ip) +{ + struct gpiohandle_request handlereq; + struct linehandle_state *lh; + struct file *file; + int fd, i, count = 0, ret; + u32 lflags; + + if (copy_from_user(&handlereq, ip, sizeof(handlereq))) + return -EFAULT; + if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX)) + return -EINVAL; + + lflags = handlereq.flags; + + ret = linehandle_validate_flags(lflags); + if (ret) + return ret; + + lh = kzalloc(sizeof(*lh), GFP_KERNEL); + if (!lh) + return -ENOMEM; + lh->gdev = gdev; + get_device(&gdev->dev); + + /* Make sure this is terminated */ + handlereq.consumer_label[sizeof(handlereq.consumer_label)-1] = '\0'; + if (strlen(handlereq.consumer_label)) { + lh->label = kstrdup(handlereq.consumer_label, + GFP_KERNEL); + if (!lh->label) { + ret = -ENOMEM; + goto out_free_lh; + } + } + + /* Request each GPIO */ + for (i = 0; i < handlereq.lines; i++) { + u32 offset = handlereq.lineoffsets[i]; + struct gpio_desc *desc = gpiochip_get_desc(gdev->chip, offset); + + if (IS_ERR(desc)) { + ret = PTR_ERR(desc); + goto out_free_descs; + } + + ret = gpiod_request(desc, lh->label); + if (ret) + goto out_free_descs; + lh->descs[i] = desc; + count = i + 1; + + if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW) + set_bit(FLAG_ACTIVE_LOW, &desc->flags); + if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) + set_bit(FLAG_OPEN_DRAIN, &desc->flags); + if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE) + set_bit(FLAG_OPEN_SOURCE, &desc->flags); + if (lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE) + set_bit(FLAG_BIAS_DISABLE, &desc->flags); + if (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN) + set_bit(FLAG_PULL_DOWN, &desc->flags); + if (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP) + set_bit(FLAG_PULL_UP, &desc->flags); + + ret = gpiod_set_transitory(desc, false); + if (ret < 0) + goto out_free_descs; + + /* + * Lines have to be requested explicitly for input + * or output, else the line will be treated "as is". + */ + if (lflags & GPIOHANDLE_REQUEST_OUTPUT) { + int val = !!handlereq.default_values[i]; + + ret = gpiod_direction_output(desc, val); + if (ret) + goto out_free_descs; + } else if (lflags & GPIOHANDLE_REQUEST_INPUT) { + ret = gpiod_direction_input(desc); + if (ret) + goto out_free_descs; + } + + atomic_notifier_call_chain(&desc->gdev->notifier, + GPIOLINE_CHANGED_REQUESTED, desc); + + dev_dbg(&gdev->dev, "registered chardev handle for line %d\n", + offset); + } + /* Let i point at the last handle */ + i--; + lh->numdescs = handlereq.lines; + + fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC); + if (fd < 0) { + ret = fd; + goto out_free_descs; + } + + file = anon_inode_getfile("gpio-linehandle", + &linehandle_fileops, + lh, + O_RDONLY | O_CLOEXEC); + if (IS_ERR(file)) { + ret = PTR_ERR(file); + goto out_put_unused_fd; + } + + handlereq.fd = fd; + if (copy_to_user(ip, &handlereq, sizeof(handlereq))) { + /* + * fput() will trigger the release() callback, so do not go onto + * the regular error cleanup path here. + */ + fput(file); + put_unused_fd(fd); + return -EFAULT; + } + + fd_install(fd, file); + + dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n", + lh->numdescs); + + return 0; + +out_put_unused_fd: + put_unused_fd(fd); +out_free_descs: + for (i = 0; i < count; i++) + gpiod_free(lh->descs[i]); + kfree(lh->label); +out_free_lh: + kfree(lh); + put_device(&gdev->dev); + return ret; +} + +/* + * GPIO line event management + */ + +/** + * struct lineevent_state - contains the state of a userspace event + * @gdev: the GPIO device the event pertains to + * @label: consumer label used to tag descriptors + * @desc: the GPIO descriptor held by this event + * @eflags: the event flags this line was requested with + * @irq: the interrupt that trigger in response to events on this GPIO + * @wait: wait queue that handles blocking reads of events + * @events: KFIFO for the GPIO events + * @timestamp: cache for the timestamp storing it between hardirq + * and IRQ thread, used to bring the timestamp close to the actual + * event + */ +struct lineevent_state { + struct gpio_device *gdev; + const char *label; + struct gpio_desc *desc; + u32 eflags; + int irq; + wait_queue_head_t wait; + DECLARE_KFIFO(events, struct gpioevent_data, 16); + u64 timestamp; +}; + +#define GPIOEVENT_REQUEST_VALID_FLAGS \ + (GPIOEVENT_REQUEST_RISING_EDGE | \ + GPIOEVENT_REQUEST_FALLING_EDGE) + +static __poll_t lineevent_poll(struct file *filep, + struct poll_table_struct *wait) +{ + struct lineevent_state *le = filep->private_data; + __poll_t events = 0; + + poll_wait(filep, &le->wait, wait); + + if (!kfifo_is_empty_spinlocked_noirqsave(&le->events, &le->wait.lock)) + events = EPOLLIN | EPOLLRDNORM; + + return events; +} + + +static ssize_t lineevent_read(struct file *filep, + char __user *buf, + size_t count, + loff_t *f_ps) +{ + struct lineevent_state *le = filep->private_data; + struct gpioevent_data ge; + ssize_t bytes_read = 0; + int ret; + + if (count < sizeof(ge)) + return -EINVAL; + + do { + spin_lock(&le->wait.lock); + if (kfifo_is_empty(&le->events)) { + if (bytes_read) { + spin_unlock(&le->wait.lock); + return bytes_read; + } + + if (filep->f_flags & O_NONBLOCK) { + spin_unlock(&le->wait.lock); + return -EAGAIN; + } + + ret = wait_event_interruptible_locked(le->wait, + !kfifo_is_empty(&le->events)); + if (ret) { + spin_unlock(&le->wait.lock); + return ret; + } + } + + ret = kfifo_out(&le->events, &ge, 1); + spin_unlock(&le->wait.lock); + if (ret != 1) { + /* + * This should never happen - we were holding the lock + * from the moment we learned the fifo is no longer + * empty until now. + */ + ret = -EIO; + break; + } + + if (copy_to_user(buf + bytes_read, &ge, sizeof(ge))) + return -EFAULT; + bytes_read += sizeof(ge); + } while (count >= bytes_read + sizeof(ge)); + + return bytes_read; +} + +static int lineevent_release(struct inode *inode, struct file *filep) +{ + struct lineevent_state *le = filep->private_data; + struct gpio_device *gdev = le->gdev; + + free_irq(le->irq, le); + gpiod_free(le->desc); + kfree(le->label); + kfree(le); + put_device(&gdev->dev); + return 0; +} + +static long lineevent_ioctl(struct file *filep, unsigned int cmd, + unsigned long arg) +{ + struct lineevent_state *le = filep->private_data; + void __user *ip = (void __user *)arg; + struct gpiohandle_data ghd; + + /* + * We can get the value for an event line but not set it, + * because it is input by definition. + */ + if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) { + int val; + + memset(&ghd, 0, sizeof(ghd)); + + val = gpiod_get_value_cansleep(le->desc); + if (val < 0) + return val; + ghd.values[0] = val; + + if (copy_to_user(ip, &ghd, sizeof(ghd))) + return -EFAULT; + + return 0; + } + return -EINVAL; +} + +#ifdef CONFIG_COMPAT +static long lineevent_ioctl_compat(struct file *filep, unsigned int cmd, + unsigned long arg) +{ + return lineevent_ioctl(filep, cmd, (unsigned long)compat_ptr(arg)); +} +#endif + +static const struct file_operations lineevent_fileops = { + .release = lineevent_release, + .read = lineevent_read, + .poll = lineevent_poll, + .owner = THIS_MODULE, + .llseek = noop_llseek, + .unlocked_ioctl = lineevent_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = lineevent_ioctl_compat, +#endif +}; + +static irqreturn_t lineevent_irq_thread(int irq, void *p) +{ + struct lineevent_state *le = p; + struct gpioevent_data ge; + int ret; + + /* Do not leak kernel stack to userspace */ + memset(&ge, 0, sizeof(ge)); + + /* + * We may be running from a nested threaded interrupt in which case + * we didn't get the timestamp from lineevent_irq_handler(). + */ + if (!le->timestamp) + ge.timestamp = ktime_get_ns(); + else + ge.timestamp = le->timestamp; + + if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE + && le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) { + int level = gpiod_get_value_cansleep(le->desc); + + if (level) + /* Emit low-to-high event */ + ge.id = GPIOEVENT_EVENT_RISING_EDGE; + else + /* Emit high-to-low event */ + ge.id = GPIOEVENT_EVENT_FALLING_EDGE; + } else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE) { + /* Emit low-to-high event */ + ge.id = GPIOEVENT_EVENT_RISING_EDGE; + } else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) { + /* Emit high-to-low event */ + ge.id = GPIOEVENT_EVENT_FALLING_EDGE; + } else { + return IRQ_NONE; + } + + ret = kfifo_in_spinlocked_noirqsave(&le->events, &ge, + 1, &le->wait.lock); + if (ret) + wake_up_poll(&le->wait, EPOLLIN); + else + pr_debug_ratelimited("event FIFO is full - event dropped\n"); + + return IRQ_HANDLED; +} + +static irqreturn_t lineevent_irq_handler(int irq, void *p) +{ + struct lineevent_state *le = p; + + /* + * Just store the timestamp in hardirq context so we get it as + * close in time as possible to the actual event. + */ + le->timestamp = ktime_get_ns(); + + return IRQ_WAKE_THREAD; +} + +static int lineevent_create(struct gpio_device *gdev, void __user *ip) +{ + struct gpioevent_request eventreq; + struct lineevent_state *le; + struct gpio_desc *desc; + struct file *file; + u32 offset; + u32 lflags; + u32 eflags; + int fd; + int ret; + int irqflags = 0; + + if (copy_from_user(&eventreq, ip, sizeof(eventreq))) + return -EFAULT; + + offset = eventreq.lineoffset; + lflags = eventreq.handleflags; + eflags = eventreq.eventflags; + + desc = gpiochip_get_desc(gdev->chip, offset); + if (IS_ERR(desc)) + return PTR_ERR(desc); + + /* Return an error if a unknown flag is set */ + if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) || + (eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS)) + return -EINVAL; + + /* This is just wrong: we don't look for events on output lines */ + if ((lflags & GPIOHANDLE_REQUEST_OUTPUT) || + (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) || + (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)) + return -EINVAL; + + /* Only one bias flag can be set. */ + if (((lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE) && + (lflags & (GPIOHANDLE_REQUEST_BIAS_PULL_DOWN | + GPIOHANDLE_REQUEST_BIAS_PULL_UP))) || + ((lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN) && + (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP))) + return -EINVAL; + + le = kzalloc(sizeof(*le), GFP_KERNEL); + if (!le) + return -ENOMEM; + le->gdev = gdev; + get_device(&gdev->dev); + + /* Make sure this is terminated */ + eventreq.consumer_label[sizeof(eventreq.consumer_label)-1] = '\0'; + if (strlen(eventreq.consumer_label)) { + le->label = kstrdup(eventreq.consumer_label, + GFP_KERNEL); + if (!le->label) { + ret = -ENOMEM; + goto out_free_le; + } + } + + ret = gpiod_request(desc, le->label); + if (ret) + goto out_free_label; + le->desc = desc; + le->eflags = eflags; + + if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW) + set_bit(FLAG_ACTIVE_LOW, &desc->flags); + if (lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE) + set_bit(FLAG_BIAS_DISABLE, &desc->flags); + if (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN) + set_bit(FLAG_PULL_DOWN, &desc->flags); + if (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP) + set_bit(FLAG_PULL_UP, &desc->flags); + + ret = gpiod_direction_input(desc); + if (ret) + goto out_free_desc; + + atomic_notifier_call_chain(&desc->gdev->notifier, + GPIOLINE_CHANGED_REQUESTED, desc); + + le->irq = gpiod_to_irq(desc); + if (le->irq <= 0) { + ret = -ENODEV; + goto out_free_desc; + } + + if (eflags & GPIOEVENT_REQUEST_RISING_EDGE) + irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? + IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING; + if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE) + irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? + IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING; + irqflags |= IRQF_ONESHOT; + + INIT_KFIFO(le->events); + init_waitqueue_head(&le->wait); + + /* Request a thread to read the events */ + ret = request_threaded_irq(le->irq, + lineevent_irq_handler, + lineevent_irq_thread, + irqflags, + le->label, + le); + if (ret) + goto out_free_desc; + + fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC); + if (fd < 0) { + ret = fd; + goto out_free_irq; + } + + file = anon_inode_getfile("gpio-event", + &lineevent_fileops, + le, + O_RDONLY | O_CLOEXEC); + if (IS_ERR(file)) { + ret = PTR_ERR(file); + goto out_put_unused_fd; + } + + eventreq.fd = fd; + if (copy_to_user(ip, &eventreq, sizeof(eventreq))) { + /* + * fput() will trigger the release() callback, so do not go onto + * the regular error cleanup path here. + */ + fput(file); + put_unused_fd(fd); + return -EFAULT; + } + + fd_install(fd, file); + + return 0; + +out_put_unused_fd: + put_unused_fd(fd); +out_free_irq: + free_irq(le->irq, le); +out_free_desc: + gpiod_free(le->desc); +out_free_label: + kfree(le->label); +out_free_le: + kfree(le); + put_device(&gdev->dev); + return ret; +} + +static void gpio_desc_to_lineinfo(struct gpio_desc *desc, + struct gpioline_info *info) +{ + struct gpio_chip *gc = desc->gdev->chip; + bool ok_for_pinctrl; + unsigned long flags; + + /* + * This function takes a mutex so we must check this before taking + * the spinlock. + * + * FIXME: find a non-racy way to retrieve this information. Maybe a + * lock common to both frameworks? + */ + ok_for_pinctrl = + pinctrl_gpio_can_use_line(gc->base + info->line_offset); + + spin_lock_irqsave(&gpio_lock, flags); + + if (desc->name) { + strncpy(info->name, desc->name, sizeof(info->name)); + info->name[sizeof(info->name) - 1] = '\0'; + } else { + info->name[0] = '\0'; + } + + if (desc->label) { + strncpy(info->consumer, desc->label, sizeof(info->consumer)); + info->consumer[sizeof(info->consumer) - 1] = '\0'; + } else { + info->consumer[0] = '\0'; + } + + /* + * Userspace only need to know that the kernel is using this GPIO so + * it can't use it. + */ + info->flags = 0; + if (test_bit(FLAG_REQUESTED, &desc->flags) || + test_bit(FLAG_IS_HOGGED, &desc->flags) || + test_bit(FLAG_USED_AS_IRQ, &desc->flags) || + test_bit(FLAG_EXPORT, &desc->flags) || + test_bit(FLAG_SYSFS, &desc->flags) || + !ok_for_pinctrl) + info->flags |= GPIOLINE_FLAG_KERNEL; + if (test_bit(FLAG_IS_OUT, &desc->flags)) + info->flags |= GPIOLINE_FLAG_IS_OUT; + if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) + info->flags |= GPIOLINE_FLAG_ACTIVE_LOW; + if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) + info->flags |= (GPIOLINE_FLAG_OPEN_DRAIN | + GPIOLINE_FLAG_IS_OUT); + if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) + info->flags |= (GPIOLINE_FLAG_OPEN_SOURCE | + GPIOLINE_FLAG_IS_OUT); + if (test_bit(FLAG_BIAS_DISABLE, &desc->flags)) + info->flags |= GPIOLINE_FLAG_BIAS_DISABLE; + if (test_bit(FLAG_PULL_DOWN, &desc->flags)) + info->flags |= GPIOLINE_FLAG_BIAS_PULL_DOWN; + if (test_bit(FLAG_PULL_UP, &desc->flags)) + info->flags |= GPIOLINE_FLAG_BIAS_PULL_UP; + + spin_unlock_irqrestore(&gpio_lock, flags); +} + +struct gpio_chardev_data { + struct gpio_device *gdev; + wait_queue_head_t wait; + DECLARE_KFIFO(events, struct gpioline_info_changed, 32); + struct notifier_block lineinfo_changed_nb; + unsigned long *watched_lines; +}; + +/* + * gpio_ioctl() - ioctl handler for the GPIO chardev + */ +static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) +{ + struct gpio_chardev_data *priv = filp->private_data; + struct gpio_device *gdev = priv->gdev; + struct gpio_chip *gc = gdev->chip; + void __user *ip = (void __user *)arg; + struct gpio_desc *desc; + __u32 offset; + int hwgpio; + + /* We fail any subsequent ioctl():s when the chip is gone */ + if (!gc) + return -ENODEV; + + /* Fill in the struct and pass to userspace */ + if (cmd == GPIO_GET_CHIPINFO_IOCTL) { + struct gpiochip_info chipinfo; + + memset(&chipinfo, 0, sizeof(chipinfo)); + + strncpy(chipinfo.name, dev_name(&gdev->dev), + sizeof(chipinfo.name)); + chipinfo.name[sizeof(chipinfo.name)-1] = '\0'; + strncpy(chipinfo.label, gdev->label, + sizeof(chipinfo.label)); + chipinfo.label[sizeof(chipinfo.label)-1] = '\0'; + chipinfo.lines = gdev->ngpio; + if (copy_to_user(ip, &chipinfo, sizeof(chipinfo))) + return -EFAULT; + return 0; + } else if (cmd == GPIO_GET_LINEINFO_IOCTL) { + struct gpioline_info lineinfo; + + if (copy_from_user(&lineinfo, ip, sizeof(lineinfo))) + return -EFAULT; + + desc = gpiochip_get_desc(gc, lineinfo.line_offset); + if (IS_ERR(desc)) + return PTR_ERR(desc); + + hwgpio = gpio_chip_hwgpio(desc); + + gpio_desc_to_lineinfo(desc, &lineinfo); + + if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) + return -EFAULT; + return 0; + } else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) { + return linehandle_create(gdev, ip); + } else if (cmd == GPIO_GET_LINEEVENT_IOCTL) { + return lineevent_create(gdev, ip); + } else if (cmd == GPIO_GET_LINEINFO_WATCH_IOCTL) { + struct gpioline_info lineinfo; + + if (copy_from_user(&lineinfo, ip, sizeof(lineinfo))) + return -EFAULT; + + desc = gpiochip_get_desc(gc, lineinfo.line_offset); + if (IS_ERR(desc)) + return PTR_ERR(desc); + + hwgpio = gpio_chip_hwgpio(desc); + + if (test_bit(hwgpio, priv->watched_lines)) + return -EBUSY; + + gpio_desc_to_lineinfo(desc, &lineinfo); + + if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) + return -EFAULT; + + set_bit(hwgpio, priv->watched_lines); + return 0; + } else if (cmd == GPIO_GET_LINEINFO_UNWATCH_IOCTL) { + if (copy_from_user(&offset, ip, sizeof(offset))) + return -EFAULT; + + desc = gpiochip_get_desc(gc, offset); + if (IS_ERR(desc)) + return PTR_ERR(desc); + + hwgpio = gpio_chip_hwgpio(desc); + + if (!test_bit(hwgpio, priv->watched_lines)) + return -EBUSY; + + clear_bit(hwgpio, priv->watched_lines); + return 0; + } + return -EINVAL; +} + +#ifdef CONFIG_COMPAT +static long gpio_ioctl_compat(struct file *filp, unsigned int cmd, + unsigned long arg) +{ + return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg)); +} +#endif + +static struct gpio_chardev_data * +to_gpio_chardev_data(struct notifier_block *nb) +{ + return container_of(nb, struct gpio_chardev_data, lineinfo_changed_nb); +} + +static int lineinfo_changed_notify(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct gpio_chardev_data *priv = to_gpio_chardev_data(nb); + struct gpioline_info_changed chg; + struct gpio_desc *desc = data; + int ret; + + if (!test_bit(gpio_chip_hwgpio(desc), priv->watched_lines)) + return NOTIFY_DONE; + + memset(&chg, 0, sizeof(chg)); + chg.info.line_offset = gpio_chip_hwgpio(desc); + chg.event_type = action; + chg.timestamp = ktime_get_ns(); + gpio_desc_to_lineinfo(desc, &chg.info); + + ret = kfifo_in_spinlocked(&priv->events, &chg, 1, &priv->wait.lock); + if (ret) + wake_up_poll(&priv->wait, EPOLLIN); + else + pr_debug_ratelimited("lineinfo event FIFO is full - event dropped\n"); + + return NOTIFY_OK; +} + +static __poll_t lineinfo_watch_poll(struct file *filep, + struct poll_table_struct *pollt) +{ + struct gpio_chardev_data *priv = filep->private_data; + __poll_t events = 0; + + poll_wait(filep, &priv->wait, pollt); + + if (!kfifo_is_empty_spinlocked_noirqsave(&priv->events, + &priv->wait.lock)) + events = EPOLLIN | EPOLLRDNORM; + + return events; +} + +static ssize_t lineinfo_watch_read(struct file *filep, char __user *buf, + size_t count, loff_t *off) +{ + struct gpio_chardev_data *priv = filep->private_data; + struct gpioline_info_changed event; + ssize_t bytes_read = 0; + int ret; + + if (count < sizeof(event)) + return -EINVAL; + + do { + spin_lock(&priv->wait.lock); + if (kfifo_is_empty(&priv->events)) { + if (bytes_read) { + spin_unlock(&priv->wait.lock); + return bytes_read; + } + + if (filep->f_flags & O_NONBLOCK) { + spin_unlock(&priv->wait.lock); + return -EAGAIN; + } + + ret = wait_event_interruptible_locked(priv->wait, + !kfifo_is_empty(&priv->events)); + if (ret) { + spin_unlock(&priv->wait.lock); + return ret; + } + } + + ret = kfifo_out(&priv->events, &event, 1); + spin_unlock(&priv->wait.lock); + if (ret != 1) { + ret = -EIO; + break; + /* We should never get here. See lineevent_read(). */ + } + + if (copy_to_user(buf + bytes_read, &event, sizeof(event))) + return -EFAULT; + bytes_read += sizeof(event); + } while (count >= bytes_read + sizeof(event)); + + return bytes_read; +} + +/** + * gpio_chrdev_open() - open the chardev for ioctl operations + * @inode: inode for this chardev + * @filp: file struct for storing private data + * Returns 0 on success + */ +static int gpio_chrdev_open(struct inode *inode, struct file *filp) +{ + struct gpio_device *gdev = container_of(inode->i_cdev, + struct gpio_device, chrdev); + struct gpio_chardev_data *priv; + int ret = -ENOMEM; + + /* Fail on open if the backing gpiochip is gone */ + if (!gdev->chip) + return -ENODEV; + + priv = kzalloc(sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->watched_lines = bitmap_zalloc(gdev->chip->ngpio, GFP_KERNEL); + if (!priv->watched_lines) + goto out_free_priv; + + init_waitqueue_head(&priv->wait); + INIT_KFIFO(priv->events); + priv->gdev = gdev; + + priv->lineinfo_changed_nb.notifier_call = lineinfo_changed_notify; + ret = atomic_notifier_chain_register(&gdev->notifier, + &priv->lineinfo_changed_nb); + if (ret) + goto out_free_bitmap; + + get_device(&gdev->dev); + filp->private_data = priv; + + ret = nonseekable_open(inode, filp); + if (ret) + goto out_unregister_notifier; + + return ret; + +out_unregister_notifier: + atomic_notifier_chain_unregister(&gdev->notifier, + &priv->lineinfo_changed_nb); +out_free_bitmap: + bitmap_free(priv->watched_lines); +out_free_priv: + kfree(priv); + return ret; +} + +/** + * gpio_chrdev_release() - close chardev after ioctl operations + * @inode: inode for this chardev + * @filp: file struct for storing private data + * Returns 0 on success + */ +static int gpio_chrdev_release(struct inode *inode, struct file *filp) +{ + struct gpio_chardev_data *priv = filp->private_data; + struct gpio_device *gdev = priv->gdev; + + bitmap_free(priv->watched_lines); + atomic_notifier_chain_unregister(&gdev->notifier, + &priv->lineinfo_changed_nb); + put_device(&gdev->dev); + kfree(priv); + + return 0; +} + +static const struct file_operations gpio_fileops = { + .release = gpio_chrdev_release, + .open = gpio_chrdev_open, + .poll = lineinfo_watch_poll, + .read = lineinfo_watch_read, + .owner = THIS_MODULE, + .llseek = no_llseek, + .unlocked_ioctl = gpio_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = gpio_ioctl_compat, +#endif +}; + +int gpiolib_cdev_register(struct gpio_device *gdev, dev_t devt) +{ + int ret; + + cdev_init(&gdev->chrdev, &gpio_fileops); + gdev->chrdev.owner = THIS_MODULE; + gdev->dev.devt = MKDEV(MAJOR(devt), gdev->id); + + ret = cdev_device_add(&gdev->chrdev, &gdev->dev); + if (ret) + return ret; + + chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n", + MAJOR(devt), gdev->id); + + return 0; +} + +void gpiolib_cdev_unregister(struct gpio_device *gdev) +{ + cdev_device_del(&gdev->chrdev, &gdev->dev); +} diff --git a/drivers/gpio/gpiolib-cdev.h b/drivers/gpio/gpiolib-cdev.h new file mode 100644 index 0000000..973578e --- /dev/null +++ b/drivers/gpio/gpiolib-cdev.h @@ -0,0 +1,11 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef GPIOLIB_CDEV_H +#define GPIOLIB_CDEV_H + +#include + +int gpiolib_cdev_register(struct gpio_device *gdev, dev_t devt); +void gpiolib_cdev_unregister(struct gpio_device *gdev); + +#endif /* GPIOLIB_CDEV_H */ diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 4fa075d..4abd751 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -17,20 +17,15 @@ #include #include #include -#include #include -#include #include -#include #include -#include -#include -#include #include #include "gpiolib.h" #include "gpiolib-of.h" #include "gpiolib-acpi.h" +#include "gpiolib-cdev.h" #define CREATE_TRACE_POINTS #include @@ -425,1105 +420,6 @@ bool gpiochip_line_is_valid(const struct gpio_chip *gc, } EXPORT_SYMBOL_GPL(gpiochip_line_is_valid); -/* - * GPIO line handle management - */ - -/** - * struct linehandle_state - contains the state of a userspace handle - * @gdev: the GPIO device the handle pertains to - * @label: consumer label used to tag descriptors - * @descs: the GPIO descriptors held by this handle - * @numdescs: the number of descriptors held in the descs array - */ -struct linehandle_state { - struct gpio_device *gdev; - const char *label; - struct gpio_desc *descs[GPIOHANDLES_MAX]; - u32 numdescs; -}; - -#define GPIOHANDLE_REQUEST_VALID_FLAGS \ - (GPIOHANDLE_REQUEST_INPUT | \ - GPIOHANDLE_REQUEST_OUTPUT | \ - GPIOHANDLE_REQUEST_ACTIVE_LOW | \ - GPIOHANDLE_REQUEST_BIAS_PULL_UP | \ - GPIOHANDLE_REQUEST_BIAS_PULL_DOWN | \ - GPIOHANDLE_REQUEST_BIAS_DISABLE | \ - GPIOHANDLE_REQUEST_OPEN_DRAIN | \ - GPIOHANDLE_REQUEST_OPEN_SOURCE) - -static int linehandle_validate_flags(u32 flags) -{ - /* Return an error if an unknown flag is set */ - if (flags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) - return -EINVAL; - - /* - * Do not allow both INPUT & OUTPUT flags to be set as they are - * contradictory. - */ - if ((flags & GPIOHANDLE_REQUEST_INPUT) && - (flags & GPIOHANDLE_REQUEST_OUTPUT)) - return -EINVAL; - - /* - * Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If - * the hardware actually supports enabling both at the same time the - * electrical result would be disastrous. - */ - if ((flags & GPIOHANDLE_REQUEST_OPEN_DRAIN) && - (flags & GPIOHANDLE_REQUEST_OPEN_SOURCE)) - return -EINVAL; - - /* OPEN_DRAIN and OPEN_SOURCE flags only make sense for output mode. */ - if (!(flags & GPIOHANDLE_REQUEST_OUTPUT) && - ((flags & GPIOHANDLE_REQUEST_OPEN_DRAIN) || - (flags & GPIOHANDLE_REQUEST_OPEN_SOURCE))) - return -EINVAL; - - /* Bias flags only allowed for input or output mode. */ - if (!((flags & GPIOHANDLE_REQUEST_INPUT) || - (flags & GPIOHANDLE_REQUEST_OUTPUT)) && - ((flags & GPIOHANDLE_REQUEST_BIAS_DISABLE) || - (flags & GPIOHANDLE_REQUEST_BIAS_PULL_UP) || - (flags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN))) - return -EINVAL; - - /* Only one bias flag can be set. */ - if (((flags & GPIOHANDLE_REQUEST_BIAS_DISABLE) && - (flags & (GPIOHANDLE_REQUEST_BIAS_PULL_DOWN | - GPIOHANDLE_REQUEST_BIAS_PULL_UP))) || - ((flags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN) && - (flags & GPIOHANDLE_REQUEST_BIAS_PULL_UP))) - return -EINVAL; - - return 0; -} - -static long linehandle_set_config(struct linehandle_state *lh, - void __user *ip) -{ - struct gpiohandle_config gcnf; - struct gpio_desc *desc; - int i, ret; - u32 lflags; - unsigned long *flagsp; - - if (copy_from_user(&gcnf, ip, sizeof(gcnf))) - return -EFAULT; - - lflags = gcnf.flags; - ret = linehandle_validate_flags(lflags); - if (ret) - return ret; - - for (i = 0; i < lh->numdescs; i++) { - desc = lh->descs[i]; - flagsp = &desc->flags; - - assign_bit(FLAG_ACTIVE_LOW, flagsp, - lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW); - - assign_bit(FLAG_OPEN_DRAIN, flagsp, - lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN); - - assign_bit(FLAG_OPEN_SOURCE, flagsp, - lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE); - - assign_bit(FLAG_PULL_UP, flagsp, - lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP); - - assign_bit(FLAG_PULL_DOWN, flagsp, - lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN); - - assign_bit(FLAG_BIAS_DISABLE, flagsp, - lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE); - - /* - * Lines have to be requested explicitly for input - * or output, else the line will be treated "as is". - */ - if (lflags & GPIOHANDLE_REQUEST_OUTPUT) { - int val = !!gcnf.default_values[i]; - - ret = gpiod_direction_output(desc, val); - if (ret) - return ret; - } else if (lflags & GPIOHANDLE_REQUEST_INPUT) { - ret = gpiod_direction_input(desc); - if (ret) - return ret; - } - - atomic_notifier_call_chain(&desc->gdev->notifier, - GPIOLINE_CHANGED_CONFIG, desc); - } - return 0; -} - -static long linehandle_ioctl(struct file *filep, unsigned int cmd, - unsigned long arg) -{ - struct linehandle_state *lh = filep->private_data; - void __user *ip = (void __user *)arg; - struct gpiohandle_data ghd; - DECLARE_BITMAP(vals, GPIOHANDLES_MAX); - int i; - - if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) { - /* NOTE: It's ok to read values of output lines. */ - int ret = gpiod_get_array_value_complex(false, - true, - lh->numdescs, - lh->descs, - NULL, - vals); - if (ret) - return ret; - - memset(&ghd, 0, sizeof(ghd)); - for (i = 0; i < lh->numdescs; i++) - ghd.values[i] = test_bit(i, vals); - - if (copy_to_user(ip, &ghd, sizeof(ghd))) - return -EFAULT; - - return 0; - } else if (cmd == GPIOHANDLE_SET_LINE_VALUES_IOCTL) { - /* - * All line descriptors were created at once with the same - * flags so just check if the first one is really output. - */ - if (!test_bit(FLAG_IS_OUT, &lh->descs[0]->flags)) - return -EPERM; - - if (copy_from_user(&ghd, ip, sizeof(ghd))) - return -EFAULT; - - /* Clamp all values to [0,1] */ - for (i = 0; i < lh->numdescs; i++) - __assign_bit(i, vals, ghd.values[i]); - - /* Reuse the array setting function */ - return gpiod_set_array_value_complex(false, - true, - lh->numdescs, - lh->descs, - NULL, - vals); - } else if (cmd == GPIOHANDLE_SET_CONFIG_IOCTL) { - return linehandle_set_config(lh, ip); - } - return -EINVAL; -} - -#ifdef CONFIG_COMPAT -static long linehandle_ioctl_compat(struct file *filep, unsigned int cmd, - unsigned long arg) -{ - return linehandle_ioctl(filep, cmd, (unsigned long)compat_ptr(arg)); -} -#endif - -static int linehandle_release(struct inode *inode, struct file *filep) -{ - struct linehandle_state *lh = filep->private_data; - struct gpio_device *gdev = lh->gdev; - int i; - - for (i = 0; i < lh->numdescs; i++) - gpiod_free(lh->descs[i]); - kfree(lh->label); - kfree(lh); - put_device(&gdev->dev); - return 0; -} - -static const struct file_operations linehandle_fileops = { - .release = linehandle_release, - .owner = THIS_MODULE, - .llseek = noop_llseek, - .unlocked_ioctl = linehandle_ioctl, -#ifdef CONFIG_COMPAT - .compat_ioctl = linehandle_ioctl_compat, -#endif -}; - -static int linehandle_create(struct gpio_device *gdev, void __user *ip) -{ - struct gpiohandle_request handlereq; - struct linehandle_state *lh; - struct file *file; - int fd, i, count = 0, ret; - u32 lflags; - - if (copy_from_user(&handlereq, ip, sizeof(handlereq))) - return -EFAULT; - if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX)) - return -EINVAL; - - lflags = handlereq.flags; - - ret = linehandle_validate_flags(lflags); - if (ret) - return ret; - - lh = kzalloc(sizeof(*lh), GFP_KERNEL); - if (!lh) - return -ENOMEM; - lh->gdev = gdev; - get_device(&gdev->dev); - - /* Make sure this is terminated */ - handlereq.consumer_label[sizeof(handlereq.consumer_label)-1] = '\0'; - if (strlen(handlereq.consumer_label)) { - lh->label = kstrdup(handlereq.consumer_label, - GFP_KERNEL); - if (!lh->label) { - ret = -ENOMEM; - goto out_free_lh; - } - } - - /* Request each GPIO */ - for (i = 0; i < handlereq.lines; i++) { - u32 offset = handlereq.lineoffsets[i]; - struct gpio_desc *desc = gpiochip_get_desc(gdev->chip, offset); - - if (IS_ERR(desc)) { - ret = PTR_ERR(desc); - goto out_free_descs; - } - - ret = gpiod_request(desc, lh->label); - if (ret) - goto out_free_descs; - lh->descs[i] = desc; - count = i + 1; - - if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW) - set_bit(FLAG_ACTIVE_LOW, &desc->flags); - if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) - set_bit(FLAG_OPEN_DRAIN, &desc->flags); - if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE) - set_bit(FLAG_OPEN_SOURCE, &desc->flags); - if (lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE) - set_bit(FLAG_BIAS_DISABLE, &desc->flags); - if (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN) - set_bit(FLAG_PULL_DOWN, &desc->flags); - if (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP) - set_bit(FLAG_PULL_UP, &desc->flags); - - ret = gpiod_set_transitory(desc, false); - if (ret < 0) - goto out_free_descs; - - /* - * Lines have to be requested explicitly for input - * or output, else the line will be treated "as is". - */ - if (lflags & GPIOHANDLE_REQUEST_OUTPUT) { - int val = !!handlereq.default_values[i]; - - ret = gpiod_direction_output(desc, val); - if (ret) - goto out_free_descs; - } else if (lflags & GPIOHANDLE_REQUEST_INPUT) { - ret = gpiod_direction_input(desc); - if (ret) - goto out_free_descs; - } - - atomic_notifier_call_chain(&desc->gdev->notifier, - GPIOLINE_CHANGED_REQUESTED, desc); - - dev_dbg(&gdev->dev, "registered chardev handle for line %d\n", - offset); - } - /* Let i point at the last handle */ - i--; - lh->numdescs = handlereq.lines; - - fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC); - if (fd < 0) { - ret = fd; - goto out_free_descs; - } - - file = anon_inode_getfile("gpio-linehandle", - &linehandle_fileops, - lh, - O_RDONLY | O_CLOEXEC); - if (IS_ERR(file)) { - ret = PTR_ERR(file); - goto out_put_unused_fd; - } - - handlereq.fd = fd; - if (copy_to_user(ip, &handlereq, sizeof(handlereq))) { - /* - * fput() will trigger the release() callback, so do not go onto - * the regular error cleanup path here. - */ - fput(file); - put_unused_fd(fd); - return -EFAULT; - } - - fd_install(fd, file); - - dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n", - lh->numdescs); - - return 0; - -out_put_unused_fd: - put_unused_fd(fd); -out_free_descs: - for (i = 0; i < count; i++) - gpiod_free(lh->descs[i]); - kfree(lh->label); -out_free_lh: - kfree(lh); - put_device(&gdev->dev); - return ret; -} - -/* - * GPIO line event management - */ - -/** - * struct lineevent_state - contains the state of a userspace event - * @gdev: the GPIO device the event pertains to - * @label: consumer label used to tag descriptors - * @desc: the GPIO descriptor held by this event - * @eflags: the event flags this line was requested with - * @irq: the interrupt that trigger in response to events on this GPIO - * @wait: wait queue that handles blocking reads of events - * @events: KFIFO for the GPIO events - * @timestamp: cache for the timestamp storing it between hardirq - * and IRQ thread, used to bring the timestamp close to the actual - * event - */ -struct lineevent_state { - struct gpio_device *gdev; - const char *label; - struct gpio_desc *desc; - u32 eflags; - int irq; - wait_queue_head_t wait; - DECLARE_KFIFO(events, struct gpioevent_data, 16); - u64 timestamp; -}; - -#define GPIOEVENT_REQUEST_VALID_FLAGS \ - (GPIOEVENT_REQUEST_RISING_EDGE | \ - GPIOEVENT_REQUEST_FALLING_EDGE) - -static __poll_t lineevent_poll(struct file *filep, - struct poll_table_struct *wait) -{ - struct lineevent_state *le = filep->private_data; - __poll_t events = 0; - - poll_wait(filep, &le->wait, wait); - - if (!kfifo_is_empty_spinlocked_noirqsave(&le->events, &le->wait.lock)) - events = EPOLLIN | EPOLLRDNORM; - - return events; -} - - -static ssize_t lineevent_read(struct file *filep, - char __user *buf, - size_t count, - loff_t *f_ps) -{ - struct lineevent_state *le = filep->private_data; - struct gpioevent_data ge; - ssize_t bytes_read = 0; - int ret; - - if (count < sizeof(ge)) - return -EINVAL; - - do { - spin_lock(&le->wait.lock); - if (kfifo_is_empty(&le->events)) { - if (bytes_read) { - spin_unlock(&le->wait.lock); - return bytes_read; - } - - if (filep->f_flags & O_NONBLOCK) { - spin_unlock(&le->wait.lock); - return -EAGAIN; - } - - ret = wait_event_interruptible_locked(le->wait, - !kfifo_is_empty(&le->events)); - if (ret) { - spin_unlock(&le->wait.lock); - return ret; - } - } - - ret = kfifo_out(&le->events, &ge, 1); - spin_unlock(&le->wait.lock); - if (ret != 1) { - /* - * This should never happen - we were holding the lock - * from the moment we learned the fifo is no longer - * empty until now. - */ - ret = -EIO; - break; - } - - if (copy_to_user(buf + bytes_read, &ge, sizeof(ge))) - return -EFAULT; - bytes_read += sizeof(ge); - } while (count >= bytes_read + sizeof(ge)); - - return bytes_read; -} - -static int lineevent_release(struct inode *inode, struct file *filep) -{ - struct lineevent_state *le = filep->private_data; - struct gpio_device *gdev = le->gdev; - - free_irq(le->irq, le); - gpiod_free(le->desc); - kfree(le->label); - kfree(le); - put_device(&gdev->dev); - return 0; -} - -static long lineevent_ioctl(struct file *filep, unsigned int cmd, - unsigned long arg) -{ - struct lineevent_state *le = filep->private_data; - void __user *ip = (void __user *)arg; - struct gpiohandle_data ghd; - - /* - * We can get the value for an event line but not set it, - * because it is input by definition. - */ - if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) { - int val; - - memset(&ghd, 0, sizeof(ghd)); - - val = gpiod_get_value_cansleep(le->desc); - if (val < 0) - return val; - ghd.values[0] = val; - - if (copy_to_user(ip, &ghd, sizeof(ghd))) - return -EFAULT; - - return 0; - } - return -EINVAL; -} - -#ifdef CONFIG_COMPAT -static long lineevent_ioctl_compat(struct file *filep, unsigned int cmd, - unsigned long arg) -{ - return lineevent_ioctl(filep, cmd, (unsigned long)compat_ptr(arg)); -} -#endif - -static const struct file_operations lineevent_fileops = { - .release = lineevent_release, - .read = lineevent_read, - .poll = lineevent_poll, - .owner = THIS_MODULE, - .llseek = noop_llseek, - .unlocked_ioctl = lineevent_ioctl, -#ifdef CONFIG_COMPAT - .compat_ioctl = lineevent_ioctl_compat, -#endif -}; - -static irqreturn_t lineevent_irq_thread(int irq, void *p) -{ - struct lineevent_state *le = p; - struct gpioevent_data ge; - int ret; - - /* Do not leak kernel stack to userspace */ - memset(&ge, 0, sizeof(ge)); - - /* - * We may be running from a nested threaded interrupt in which case - * we didn't get the timestamp from lineevent_irq_handler(). - */ - if (!le->timestamp) - ge.timestamp = ktime_get_ns(); - else - ge.timestamp = le->timestamp; - - if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE - && le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) { - int level = gpiod_get_value_cansleep(le->desc); - if (level) - /* Emit low-to-high event */ - ge.id = GPIOEVENT_EVENT_RISING_EDGE; - else - /* Emit high-to-low event */ - ge.id = GPIOEVENT_EVENT_FALLING_EDGE; - } else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE) { - /* Emit low-to-high event */ - ge.id = GPIOEVENT_EVENT_RISING_EDGE; - } else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) { - /* Emit high-to-low event */ - ge.id = GPIOEVENT_EVENT_FALLING_EDGE; - } else { - return IRQ_NONE; - } - - ret = kfifo_in_spinlocked_noirqsave(&le->events, &ge, - 1, &le->wait.lock); - if (ret) - wake_up_poll(&le->wait, EPOLLIN); - else - pr_debug_ratelimited("event FIFO is full - event dropped\n"); - - return IRQ_HANDLED; -} - -static irqreturn_t lineevent_irq_handler(int irq, void *p) -{ - struct lineevent_state *le = p; - - /* - * Just store the timestamp in hardirq context so we get it as - * close in time as possible to the actual event. - */ - le->timestamp = ktime_get_ns(); - - return IRQ_WAKE_THREAD; -} - -static int lineevent_create(struct gpio_device *gdev, void __user *ip) -{ - struct gpioevent_request eventreq; - struct lineevent_state *le; - struct gpio_desc *desc; - struct file *file; - u32 offset; - u32 lflags; - u32 eflags; - int fd; - int ret; - int irqflags = 0; - - if (copy_from_user(&eventreq, ip, sizeof(eventreq))) - return -EFAULT; - - offset = eventreq.lineoffset; - lflags = eventreq.handleflags; - eflags = eventreq.eventflags; - - desc = gpiochip_get_desc(gdev->chip, offset); - if (IS_ERR(desc)) - return PTR_ERR(desc); - - /* Return an error if a unknown flag is set */ - if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) || - (eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS)) - return -EINVAL; - - /* This is just wrong: we don't look for events on output lines */ - if ((lflags & GPIOHANDLE_REQUEST_OUTPUT) || - (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) || - (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)) - return -EINVAL; - - /* Only one bias flag can be set. */ - if (((lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE) && - (lflags & (GPIOHANDLE_REQUEST_BIAS_PULL_DOWN | - GPIOHANDLE_REQUEST_BIAS_PULL_UP))) || - ((lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN) && - (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP))) - return -EINVAL; - - le = kzalloc(sizeof(*le), GFP_KERNEL); - if (!le) - return -ENOMEM; - le->gdev = gdev; - get_device(&gdev->dev); - - /* Make sure this is terminated */ - eventreq.consumer_label[sizeof(eventreq.consumer_label)-1] = '\0'; - if (strlen(eventreq.consumer_label)) { - le->label = kstrdup(eventreq.consumer_label, - GFP_KERNEL); - if (!le->label) { - ret = -ENOMEM; - goto out_free_le; - } - } - - ret = gpiod_request(desc, le->label); - if (ret) - goto out_free_label; - le->desc = desc; - le->eflags = eflags; - - if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW) - set_bit(FLAG_ACTIVE_LOW, &desc->flags); - if (lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE) - set_bit(FLAG_BIAS_DISABLE, &desc->flags); - if (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN) - set_bit(FLAG_PULL_DOWN, &desc->flags); - if (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP) - set_bit(FLAG_PULL_UP, &desc->flags); - - ret = gpiod_direction_input(desc); - if (ret) - goto out_free_desc; - - atomic_notifier_call_chain(&desc->gdev->notifier, - GPIOLINE_CHANGED_REQUESTED, desc); - - le->irq = gpiod_to_irq(desc); - if (le->irq <= 0) { - ret = -ENODEV; - goto out_free_desc; - } - - if (eflags & GPIOEVENT_REQUEST_RISING_EDGE) - irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? - IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING; - if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE) - irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? - IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING; - irqflags |= IRQF_ONESHOT; - - INIT_KFIFO(le->events); - init_waitqueue_head(&le->wait); - - /* Request a thread to read the events */ - ret = request_threaded_irq(le->irq, - lineevent_irq_handler, - lineevent_irq_thread, - irqflags, - le->label, - le); - if (ret) - goto out_free_desc; - - fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC); - if (fd < 0) { - ret = fd; - goto out_free_irq; - } - - file = anon_inode_getfile("gpio-event", - &lineevent_fileops, - le, - O_RDONLY | O_CLOEXEC); - if (IS_ERR(file)) { - ret = PTR_ERR(file); - goto out_put_unused_fd; - } - - eventreq.fd = fd; - if (copy_to_user(ip, &eventreq, sizeof(eventreq))) { - /* - * fput() will trigger the release() callback, so do not go onto - * the regular error cleanup path here. - */ - fput(file); - put_unused_fd(fd); - return -EFAULT; - } - - fd_install(fd, file); - - return 0; - -out_put_unused_fd: - put_unused_fd(fd); -out_free_irq: - free_irq(le->irq, le); -out_free_desc: - gpiod_free(le->desc); -out_free_label: - kfree(le->label); -out_free_le: - kfree(le); - put_device(&gdev->dev); - return ret; -} - -static void gpio_desc_to_lineinfo(struct gpio_desc *desc, - struct gpioline_info *info) -{ - struct gpio_chip *gc = desc->gdev->chip; - bool ok_for_pinctrl; - unsigned long flags; - - /* - * This function takes a mutex so we must check this before taking - * the spinlock. - * - * FIXME: find a non-racy way to retrieve this information. Maybe a - * lock common to both frameworks? - */ - ok_for_pinctrl = - pinctrl_gpio_can_use_line(gc->base + info->line_offset); - - spin_lock_irqsave(&gpio_lock, flags); - - if (desc->name) { - strncpy(info->name, desc->name, sizeof(info->name)); - info->name[sizeof(info->name) - 1] = '\0'; - } else { - info->name[0] = '\0'; - } - - if (desc->label) { - strncpy(info->consumer, desc->label, sizeof(info->consumer)); - info->consumer[sizeof(info->consumer) - 1] = '\0'; - } else { - info->consumer[0] = '\0'; - } - - /* - * Userspace only need to know that the kernel is using this GPIO so - * it can't use it. - */ - info->flags = 0; - if (test_bit(FLAG_REQUESTED, &desc->flags) || - test_bit(FLAG_IS_HOGGED, &desc->flags) || - test_bit(FLAG_USED_AS_IRQ, &desc->flags) || - test_bit(FLAG_EXPORT, &desc->flags) || - test_bit(FLAG_SYSFS, &desc->flags) || - !ok_for_pinctrl) - info->flags |= GPIOLINE_FLAG_KERNEL; - if (test_bit(FLAG_IS_OUT, &desc->flags)) - info->flags |= GPIOLINE_FLAG_IS_OUT; - if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) - info->flags |= GPIOLINE_FLAG_ACTIVE_LOW; - if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) - info->flags |= (GPIOLINE_FLAG_OPEN_DRAIN | - GPIOLINE_FLAG_IS_OUT); - if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) - info->flags |= (GPIOLINE_FLAG_OPEN_SOURCE | - GPIOLINE_FLAG_IS_OUT); - if (test_bit(FLAG_BIAS_DISABLE, &desc->flags)) - info->flags |= GPIOLINE_FLAG_BIAS_DISABLE; - if (test_bit(FLAG_PULL_DOWN, &desc->flags)) - info->flags |= GPIOLINE_FLAG_BIAS_PULL_DOWN; - if (test_bit(FLAG_PULL_UP, &desc->flags)) - info->flags |= GPIOLINE_FLAG_BIAS_PULL_UP; - - spin_unlock_irqrestore(&gpio_lock, flags); -} - -struct gpio_chardev_data { - struct gpio_device *gdev; - wait_queue_head_t wait; - DECLARE_KFIFO(events, struct gpioline_info_changed, 32); - struct notifier_block lineinfo_changed_nb; - unsigned long *watched_lines; -}; - -/* - * gpio_ioctl() - ioctl handler for the GPIO chardev - */ -static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) -{ - struct gpio_chardev_data *priv = filp->private_data; - struct gpio_device *gdev = priv->gdev; - struct gpio_chip *gc = gdev->chip; - void __user *ip = (void __user *)arg; - struct gpio_desc *desc; - __u32 offset; - int hwgpio; - - /* We fail any subsequent ioctl():s when the chip is gone */ - if (!gc) - return -ENODEV; - - /* Fill in the struct and pass to userspace */ - if (cmd == GPIO_GET_CHIPINFO_IOCTL) { - struct gpiochip_info chipinfo; - - memset(&chipinfo, 0, sizeof(chipinfo)); - - strncpy(chipinfo.name, dev_name(&gdev->dev), - sizeof(chipinfo.name)); - chipinfo.name[sizeof(chipinfo.name)-1] = '\0'; - strncpy(chipinfo.label, gdev->label, - sizeof(chipinfo.label)); - chipinfo.label[sizeof(chipinfo.label)-1] = '\0'; - chipinfo.lines = gdev->ngpio; - if (copy_to_user(ip, &chipinfo, sizeof(chipinfo))) - return -EFAULT; - return 0; - } else if (cmd == GPIO_GET_LINEINFO_IOCTL) { - struct gpioline_info lineinfo; - - if (copy_from_user(&lineinfo, ip, sizeof(lineinfo))) - return -EFAULT; - - desc = gpiochip_get_desc(gc, lineinfo.line_offset); - if (IS_ERR(desc)) - return PTR_ERR(desc); - - hwgpio = gpio_chip_hwgpio(desc); - - gpio_desc_to_lineinfo(desc, &lineinfo); - - if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) - return -EFAULT; - return 0; - } else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) { - return linehandle_create(gdev, ip); - } else if (cmd == GPIO_GET_LINEEVENT_IOCTL) { - return lineevent_create(gdev, ip); - } else if (cmd == GPIO_GET_LINEINFO_WATCH_IOCTL) { - struct gpioline_info lineinfo; - - if (copy_from_user(&lineinfo, ip, sizeof(lineinfo))) - return -EFAULT; - - desc = gpiochip_get_desc(gc, lineinfo.line_offset); - if (IS_ERR(desc)) - return PTR_ERR(desc); - - hwgpio = gpio_chip_hwgpio(desc); - - if (test_bit(hwgpio, priv->watched_lines)) - return -EBUSY; - - gpio_desc_to_lineinfo(desc, &lineinfo); - - if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) - return -EFAULT; - - set_bit(hwgpio, priv->watched_lines); - return 0; - } else if (cmd == GPIO_GET_LINEINFO_UNWATCH_IOCTL) { - if (copy_from_user(&offset, ip, sizeof(offset))) - return -EFAULT; - - desc = gpiochip_get_desc(gc, offset); - if (IS_ERR(desc)) - return PTR_ERR(desc); - - hwgpio = gpio_chip_hwgpio(desc); - - if (!test_bit(hwgpio, priv->watched_lines)) - return -EBUSY; - - clear_bit(hwgpio, priv->watched_lines); - return 0; - } - return -EINVAL; -} - -#ifdef CONFIG_COMPAT -static long gpio_ioctl_compat(struct file *filp, unsigned int cmd, - unsigned long arg) -{ - return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg)); -} -#endif - -static struct gpio_chardev_data * -to_gpio_chardev_data(struct notifier_block *nb) -{ - return container_of(nb, struct gpio_chardev_data, lineinfo_changed_nb); -} - -static int lineinfo_changed_notify(struct notifier_block *nb, - unsigned long action, void *data) -{ - struct gpio_chardev_data *priv = to_gpio_chardev_data(nb); - struct gpioline_info_changed chg; - struct gpio_desc *desc = data; - int ret; - - if (!test_bit(gpio_chip_hwgpio(desc), priv->watched_lines)) - return NOTIFY_DONE; - - memset(&chg, 0, sizeof(chg)); - chg.info.line_offset = gpio_chip_hwgpio(desc); - chg.event_type = action; - chg.timestamp = ktime_get_ns(); - gpio_desc_to_lineinfo(desc, &chg.info); - - ret = kfifo_in_spinlocked(&priv->events, &chg, 1, &priv->wait.lock); - if (ret) - wake_up_poll(&priv->wait, EPOLLIN); - else - pr_debug_ratelimited("lineinfo event FIFO is full - event dropped\n"); - - return NOTIFY_OK; -} - -static __poll_t lineinfo_watch_poll(struct file *filep, - struct poll_table_struct *pollt) -{ - struct gpio_chardev_data *priv = filep->private_data; - __poll_t events = 0; - - poll_wait(filep, &priv->wait, pollt); - - if (!kfifo_is_empty_spinlocked_noirqsave(&priv->events, - &priv->wait.lock)) - events = EPOLLIN | EPOLLRDNORM; - - return events; -} - -static ssize_t lineinfo_watch_read(struct file *filep, char __user *buf, - size_t count, loff_t *off) -{ - struct gpio_chardev_data *priv = filep->private_data; - struct gpioline_info_changed event; - ssize_t bytes_read = 0; - int ret; - - if (count < sizeof(event)) - return -EINVAL; - - do { - spin_lock(&priv->wait.lock); - if (kfifo_is_empty(&priv->events)) { - if (bytes_read) { - spin_unlock(&priv->wait.lock); - return bytes_read; - } - - if (filep->f_flags & O_NONBLOCK) { - spin_unlock(&priv->wait.lock); - return -EAGAIN; - } - - ret = wait_event_interruptible_locked(priv->wait, - !kfifo_is_empty(&priv->events)); - if (ret) { - spin_unlock(&priv->wait.lock); - return ret; - } - } - - ret = kfifo_out(&priv->events, &event, 1); - spin_unlock(&priv->wait.lock); - if (ret != 1) { - ret = -EIO; - break; - /* We should never get here. See lineevent_read(). */ - } - - if (copy_to_user(buf + bytes_read, &event, sizeof(event))) - return -EFAULT; - bytes_read += sizeof(event); - } while (count >= bytes_read + sizeof(event)); - - return bytes_read; -} - -/** - * gpio_chrdev_open() - open the chardev for ioctl operations - * @inode: inode for this chardev - * @filp: file struct for storing private data - * Returns 0 on success - */ -static int gpio_chrdev_open(struct inode *inode, struct file *filp) -{ - struct gpio_device *gdev = container_of(inode->i_cdev, - struct gpio_device, chrdev); - struct gpio_chardev_data *priv; - int ret = -ENOMEM; - - /* Fail on open if the backing gpiochip is gone */ - if (!gdev->chip) - return -ENODEV; - - priv = kzalloc(sizeof(*priv), GFP_KERNEL); - if (!priv) - return -ENOMEM; - - priv->watched_lines = bitmap_zalloc(gdev->chip->ngpio, GFP_KERNEL); - if (!priv->watched_lines) - goto out_free_priv; - - init_waitqueue_head(&priv->wait); - INIT_KFIFO(priv->events); - priv->gdev = gdev; - - priv->lineinfo_changed_nb.notifier_call = lineinfo_changed_notify; - ret = atomic_notifier_chain_register(&gdev->notifier, - &priv->lineinfo_changed_nb); - if (ret) - goto out_free_bitmap; - - get_device(&gdev->dev); - filp->private_data = priv; - - ret = nonseekable_open(inode, filp); - if (ret) - goto out_unregister_notifier; - - return ret; - -out_unregister_notifier: - atomic_notifier_chain_unregister(&gdev->notifier, - &priv->lineinfo_changed_nb); -out_free_bitmap: - bitmap_free(priv->watched_lines); -out_free_priv: - kfree(priv); - return ret; -} - -/** - * gpio_chrdev_release() - close chardev after ioctl operations - * @inode: inode for this chardev - * @filp: file struct for storing private data - * Returns 0 on success - */ -static int gpio_chrdev_release(struct inode *inode, struct file *filp) -{ - struct gpio_chardev_data *priv = filp->private_data; - struct gpio_device *gdev = priv->gdev; - - bitmap_free(priv->watched_lines); - atomic_notifier_chain_unregister(&gdev->notifier, - &priv->lineinfo_changed_nb); - put_device(&gdev->dev); - kfree(priv); - - return 0; -} - -static const struct file_operations gpio_fileops = { - .release = gpio_chrdev_release, - .open = gpio_chrdev_open, - .poll = lineinfo_watch_poll, - .read = lineinfo_watch_read, - .owner = THIS_MODULE, - .llseek = no_llseek, - .unlocked_ioctl = gpio_ioctl, -#ifdef CONFIG_COMPAT - .compat_ioctl = gpio_ioctl_compat, -#endif -}; - static void gpiodevice_release(struct device *dev) { struct gpio_device *gdev = dev_get_drvdata(dev); @@ -1539,17 +435,10 @@ static int gpiochip_setup_dev(struct gpio_device *gdev) { int ret; - cdev_init(&gdev->chrdev, &gpio_fileops); - gdev->chrdev.owner = THIS_MODULE; - gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id); - - ret = cdev_device_add(&gdev->chrdev, &gdev->dev); + ret = gpiolib_cdev_register(gdev, gpio_devt); if (ret) return ret; - chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n", - MAJOR(gpio_devt), gdev->id); - ret = gpiochip_sysfs_register(gdev); if (ret) goto err_remove_device; @@ -1562,7 +451,7 @@ static int gpiochip_setup_dev(struct gpio_device *gdev) return 0; err_remove_device: - cdev_device_del(&gdev->chrdev, &gdev->dev); + gpiolib_cdev_unregister(gdev); return ret; } @@ -1884,7 +773,7 @@ void gpiochip_remove(struct gpio_chip *gc) * be removed, else it will be dangling until the last user is * gone. */ - cdev_device_del(&gdev->chrdev, &gdev->dev); + gpiolib_cdev_unregister(gdev); put_device(&gdev->dev); } EXPORT_SYMBOL_GPL(gpiochip_remove); -- 2.7.4